mirror of
https://github.com/johnkerl/miller.git
synced 2026-01-23 02:14:13 +00:00
a977617797
* address some staticcheck issues * address some staticcheck issues * address some staticcheck issues * address some staticcheck issues
103 lines
2.4 KiB
BNF
103 lines
2.4 KiB
BNF
// ================================================================
|
|
// LEXER
|
|
|
|
!whitespace : ' ' | '\t' | '\n' | '\r' ;
|
|
!comment : '#' {.} '\n' ;
|
|
|
|
_letter : 'a'-'z' | 'A'-'Z' ;
|
|
_decdig : '0'-'9' ;
|
|
_idchar : _letter | _decdig | '_' ;
|
|
|
|
emit : 'e' 'm' 'i' 't' ;
|
|
|
|
// ================================================================
|
|
// IMPORT
|
|
|
|
<< import "miller/src/dsl" >>
|
|
|
|
// ================================================================
|
|
// PARSER
|
|
|
|
// ----------------------------------------------------------------
|
|
Root
|
|
: EmitStatement
|
|
<< dsl.NewAST($0) >>
|
|
;
|
|
|
|
// ----------------------------------------------------------------
|
|
// Examples:
|
|
// emit @a
|
|
// emit (@a, @b)
|
|
// emit @a, "x", "y"
|
|
// emit (@a, @b), "x", "y"
|
|
// First argument (single or in parentheses) must be non-indexed
|
|
// oosvar/localvar/fieldname, so we can use their names as keys in the emitted
|
|
// record. These restrictions are enforced in the CST logic, to keep this
|
|
// parser/AST logic simpler.
|
|
EmitStatement
|
|
: emit Rvalue
|
|
<< dsl.NewASTNodeUnary($0, $1, dsl.NodeTypeEmitStatement) >>
|
|
|
|
| emit Rvalue "," EmitArgs
|
|
<< dsl.NewASTNodeBinary($0, $1, $3, dsl.NodeTypeEmitStatement) >>
|
|
|
|
| emit "(" EmitArgs ")"
|
|
<< dsl.NewASTNodeUnary($0, $2, dsl.NodeTypeEmitStatement) >>
|
|
|
|
| emit "(" EmitArgs ")" "," EmitArgs
|
|
<< dsl.NewASTNodeBinary($0, $2, $5, dsl.NodeTypeEmitStatement) >>
|
|
;
|
|
|
|
// ----------------------------------------------------------------
|
|
EmitArgs
|
|
: Rvalue
|
|
<< dsl.NewASTNodeUnary(
|
|
nil,
|
|
$0,
|
|
dsl.NodeTypeFunctionCallsite,
|
|
) >>
|
|
|
|
| Rvalue "," EmitArgs
|
|
<< dsl.PrependChild(
|
|
$2,
|
|
$0,
|
|
) >>
|
|
;
|
|
|
|
// ----------------------------------------------------------------
|
|
FcnArgs
|
|
: Rvalue
|
|
<< dsl.NewASTNodeUnary(
|
|
nil,
|
|
$0,
|
|
dsl.NodeTypeFunctionCallsite,
|
|
) >>
|
|
|
|
// Allow trailing final comma, especially for multiline statements
|
|
| Rvalue ","
|
|
<< dsl.NewASTNodeUnary(
|
|
nil,
|
|
$0,
|
|
dsl.NodeTypeFunctionCallsite,
|
|
) >>
|
|
|
|
// Allow trailing final comma, especially for multiline statements
|
|
| Rvalue "," FcnArgs
|
|
<< dsl.PrependChild(
|
|
$2,
|
|
$0,
|
|
) >>
|
|
;
|
|
|
|
|
|
// ----------------------------------------------------------------
|
|
Rvalue
|
|
: Literal
|
|
| "(" Literal ")"
|
|
;
|
|
|
|
Literal
|
|
: "x" << dsl.NewASTNodeZary($0, dsl.NodeTypeStringLiteral) >>
|
|
| "y" << dsl.NewASTNodeZary($0, dsl.NodeTypeStringLiteral) >>
|
|
| "z" << dsl.NewASTNodeZary($0, dsl.NodeTypeStringLiteral) >>
|
|
;
|